1. Field of the Invention
The invention relates to an impact damper for vehicles, in particular for supporting a bumper of a vehicle on the latter's chassis.
2. Background Art
The connection in series of a reversible impact damper with an irreversible deformation damper is known from U.S. Pat. No. 5,181,589, the piston rod of the reversible impact damper bearing at its free end against a pressure plate which in turn bears against inwards projecting crimps of a tube. The latter are deformed outwards when the pressure plate is pushed through.
A deformation damper is known from U.S. Pat. No. 4,445,708 which has an inner tube and an outer tube. A ball cage is arranged between the inner and the outer tube; the outer tube has a conical section. When the two tubes are pushed together, the balls of the ball cage get into this conical section and deform it. This deformation damper is extraordinarily expensive.
Deformation dampers are known from U.S. Pat. No. 3,482,653 which have a deformation tube provided with a tapering or depression and a further tube provided with one or several rings which, when the deformation tube is pushed into the other tube, deform the deformation tube plastically by necking.